This invention relates to self-steering bogies for trailers, and particularly to bogies in which their loads are applied through flexible supporting means to respective pairs of tandem axles, and the axles of each of the pairs are displaced in opposite directions for steering.
Both axles of a bogie are turned for steering according to the arrangement described in U.S. Pat. No. 3,338,592 issued to W. Hildebrandt et al on Aug. 29, 1967. A main frame of a trailer is supported on a separate frame of a bogie by pivotal plates or a turntable, and the separate frame of the bogie is supported by a front and a rear turntable on a front and a rear axle-and-wheel assembly, respectively. An arrangement of linkages is connected from the main frame through the turntable that immediately supports the main frame to each of the turntables supported by the respective front and rear axles of the bogie. In response to rotation of the main frame with respect to the separate frame of the bogie, the axles are turned in opposite directions to follow without slippage of their wheels a curved path determined by the amount of turning of a forward tractor. Steering of both axles of bogies decreases tire wear, decreases the amount of power required to turn trailers, decreases the bending strain on the trailers, and steers the trailers to track more closely the tractors to help maintain the trailers safely in curved traffic lanes.